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- Extracted ASN.1 parsing code from the X.509 parsing code. Added new module.

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This commit is contained in:
Paul Bakker 2011-11-10 14:43:23 +00:00
parent b125ed8fc6
commit efc302964c
8 changed files with 526 additions and 293 deletions
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2
ChangeLog
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@ -16,6 +16,8 @@ Changes
* Inceased maximum size of ASN1 length reads to 32-bits. * Inceased maximum size of ASN1 length reads to 32-bits.
* Added an EXPLICIT tag number parameter to x509_get_ext() * Added an EXPLICIT tag number parameter to x509_get_ext()
* Added a separate CRL entry extension parsing function * Added a separate CRL entry extension parsing function
* Separated the ASN.1 parsing code from the X.509 specific parsing code.
So now there is a module that is controlled with POLARSSL_ASN1_PARSE_C.
Bugfix Bugfix
* Fixed faulty HMAC-MD2 implementation. Found by dibac. (Closes * Fixed faulty HMAC-MD2 implementation. Found by dibac. (Closes

242
include/polarssl/asn1.h Normal file
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@ -0,0 +1,242 @@
/**
* \file asn1.h
*
* \brief Generic ASN.1 parsing
*
* Copyright (C) 2006-2011, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef POLARSSL_ASN1_H
#define POLARSSL_ASN1_H
#include "polarssl/config.h"
#if defined(POLARSSL_BIGNUM_C)
#include "polarssl/bignum.h"
#endif
#include <string.h>
/**
* \addtogroup asn1_module
* \{
*/
/**
* \name ASN1 Error codes
* These error codes are OR'ed to X509 error codes for
* higher error granularity.
* ASN1 is a standard to specify data structures.
* \{
*/
#define POLARSSL_ERR_ASN1_OUT_OF_DATA -0x0014 /**< Out of data when parsing an ASN1 data structure. */
#define POLARSSL_ERR_ASN1_UNEXPECTED_TAG -0x0016 /**< ASN1 tag was of an unexpected value. */
#define POLARSSL_ERR_ASN1_INVALID_LENGTH -0x0018 /**< Error when trying to determine the length or invalid length. */
#define POLARSSL_ERR_ASN1_LENGTH_MISMATCH -0x001A /**< Actual length differs from expected length. */
#define POLARSSL_ERR_ASN1_INVALID_DATA -0x001C /**< Data is invalid. (not used) */
/* \} name */
/**
* \name DER constants
* These constants comply with DER encoded the ANS1 type tags.
* DER encoding uses hexadecimal representation.
* An example DER sequence is:\n
* - 0x02 -- tag indicating INTEGER
* - 0x01 -- length in octets
* - 0x05 -- value
* Such sequences are typically read into \c ::x509_buf.
* \{
*/
#define ASN1_BOOLEAN 0x01
#define ASN1_INTEGER 0x02
#define ASN1_BIT_STRING 0x03
#define ASN1_OCTET_STRING 0x04
#define ASN1_NULL 0x05
#define ASN1_OID 0x06
#define ASN1_UTF8_STRING 0x0C
#define ASN1_SEQUENCE 0x10
#define ASN1_SET 0x11
#define ASN1_PRINTABLE_STRING 0x13
#define ASN1_T61_STRING 0x14
#define ASN1_IA5_STRING 0x16
#define ASN1_UTC_TIME 0x17
#define ASN1_GENERALIZED_TIME 0x18
#define ASN1_UNIVERSAL_STRING 0x1C
#define ASN1_BMP_STRING 0x1E
#define ASN1_PRIMITIVE 0x00
#define ASN1_CONSTRUCTED 0x20
#define ASN1_CONTEXT_SPECIFIC 0x80
/* \} name */
/* \} addtogroup asn1_module */
/** Returns the size of the binary string, without the trailing \\0 */
#define OID_SIZE(x) (sizeof(x) - 1)
#ifdef __cplusplus
extern "C" {
#endif
/**
* \name Functions to parse ASN.1 data structures
* \{
*/
/**
* Type-length-value structure that allows for ASN1 using DER.
*/
typedef struct _asn1_buf
{
int tag; /**< ASN1 type, e.g. ASN1_UTF8_STRING. */
size_t len; /**< ASN1 length, e.g. in octets. */
unsigned char *p; /**< ASN1 data, e.g. in ASCII. */
}
asn1_buf;
/**
* Container for ASN1 bit strings.
*/
typedef struct _asn1_bitstring
{
size_t len; /**< ASN1 length, e.g. in octets. */
unsigned char unused_bits; /**< Number of unused bits at the end of the string */
unsigned char *p; /**< Raw ASN1 data for the bit string */
}
asn1_bitstring;
/**
* Container for a sequence of ASN.1 items
*/
typedef struct _asn1_sequence
{
asn1_buf buf; /**< Buffer containing the given ASN.1 item. */
struct _asn1_sequence *next; /**< The next entry in the sequence. */
}
asn1_sequence;
/**
* Get the length of an ASN.1 element.
* Updates the pointer to immediately behind the length.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param len The variable that will receive the value
*
* \return 0 if successful, POLARSSL_ERR_ASN1_OUT_OF_DATA on reaching
* end of data, POLARSSL_ERR_ASN1_INVALID_LENGTH if length is
* unparseable.
*/
int asn1_get_len( unsigned char **p,
const unsigned char *end,
size_t *len );
/**
* Get the tag and length of the tag. Check for the requested tag.
* Updates the pointer to immediately behind the tag and length.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param len The variable that will receive the length
* \param tag The expected tag
*
* \return 0 if successful, POLARSSL_ERR_ASN1_UNEXPECTED_TAG if tag did
* not match requested tag, or another specific ASN.1 error code.
*/
int asn1_get_tag( unsigned char **p,
const unsigned char *end,
size_t *len, int tag );
/**
* Retrieve a boolean ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param val The variable that will receive the value
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_bool( unsigned char **p,
const unsigned char *end,
int *val );
/**
* Retrieve an integer ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param val The variable that will receive the value
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val );
/**
* Retrieve a bitstring ASN.1 tag and its value.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param bs The variable that will receive the value
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
asn1_bitstring *bs);
/**
* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
* Updated the pointer to immediately behind the full sequence tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param cur First variable in the chain to fill
*
* \return 0 if successful or a specific ASN.1 error code.
*/
int asn1_get_sequence_of( unsigned char **p,
const unsigned char *end,
asn1_sequence *cur,
int tag);
#if defined(POLARSSL_BIGNUM_C)
/**
* Retrieve a MPI value from an integer ASN.1 tag.
* Updates the pointer to immediately behind the full tag.
*
* \param p The position in the ASN.1 data
* \param end End of data
* \param X The MPI that will receive the value
*
* \return 0 if successful or a specific ASN.1 or MPI error code.
*/
int asn1_get_mpi( unsigned char **p,
const unsigned char *end,
mpi *X );
#endif
#ifdef __cplusplus
}
#endif
#endif /* asn1.h */

14
include/polarssl/config.h
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@ -3,7 +3,7 @@
* *
* \brief Configuration options (set of defines) * \brief Configuration options (set of defines)
* *
* Copyright (C) 2006-2010, Brainspark B.V. * Copyright (C) 2006-2011, Brainspark B.V.
* *
* This file is part of PolarSSL (http://www.polarssl.org) * This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@ -230,6 +230,16 @@
*/ */
#define POLARSSL_ARC4_C #define POLARSSL_ARC4_C
/**
* \def POLARSSL_ASN1_PARSE_C
*
* Enable the generic ASN1 parser.
*
* Module: library/asn1.c
* Caller: library/x509parse.c
*/
#define POLARSSL_ASN1_PARSE_C
/** /**
* \def POLARSSL_BASE64_C * \def POLARSSL_BASE64_C
* *
@ -605,7 +615,7 @@
* library/ssl_srv.c * library/ssl_srv.c
* library/ssl_tls.c * library/ssl_tls.c
* *
* Requires: POLARSSL_BIGNUM_C, POLARSSL_RSA_C * Requires: POLARSSL_ASN1_PARSE_C, POLARSSL_BIGNUM_C, POLARSSL_RSA_C
* *
* This module is required for X.509 certificate parsing. * This module is required for X.509 certificate parsing.
*/ */

76
include/polarssl/x509.h
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@ -3,7 +3,7 @@
* *
* \brief X.509 certificate and private key decoding * \brief X.509 certificate and private key decoding
* *
* Copyright (C) 2006-2010, Brainspark B.V. * Copyright (C) 2006-2011, Brainspark B.V.
* *
* This file is part of PolarSSL (http://www.polarssl.org) * This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@ -27,6 +27,7 @@
#ifndef POLARSSL_X509_H #ifndef POLARSSL_X509_H
#define POLARSSL_X509_H #define POLARSSL_X509_H
#include "asn1.h"
#include "rsa.h" #include "rsa.h"
#include "dhm.h" #include "dhm.h"
@ -35,20 +36,6 @@
* \{ * \{
*/ */
/**
* \name ASN1 Error codes
* These error codes are OR'ed to X509 error codes for
* higher error granularity.
* ASN1 is a standard to specify data structures.
* \{
*/
#define POLARSSL_ERR_ASN1_OUT_OF_DATA -0x0014 /**< Out of data when parsing an ASN1 data structure. */
#define POLARSSL_ERR_ASN1_UNEXPECTED_TAG -0x0016 /**< ASN1 tag was of an unexpected value. */
#define POLARSSL_ERR_ASN1_INVALID_LENGTH -0x0018 /**< Error when trying to determine the length or invalid length. */
#define POLARSSL_ERR_ASN1_LENGTH_MISMATCH -0x001A /**< Actual length differs from expected length. */
#define POLARSSL_ERR_ASN1_INVALID_DATA -0x001C /**< Data is invalid. (not used) */
/* \} name */
/** /**
* \name X509 Error codes * \name X509 Error codes
* \{ * \{
@ -89,39 +76,6 @@
#define BADCERT_MISSING 0x40 /**< Certificate was missing. */ #define BADCERT_MISSING 0x40 /**< Certificate was missing. */
#define BADCERT_SKIP_VERIFY 0x80 /**< Certificate verification was skipped. */ #define BADCERT_SKIP_VERIFY 0x80 /**< Certificate verification was skipped. */
/* \} name */ /* \} name */
/**
* \name DER constants
* These constants comply with DER encoded the ANS1 type tags.
* DER encoding uses hexadecimal representation.
* An example DER sequence is:\n
* - 0x02 -- tag indicating INTEGER
* - 0x01 -- length in octets
* - 0x05 -- value
* Such sequences are typically read into \c ::x509_buf.
* \{
*/
#define ASN1_BOOLEAN 0x01
#define ASN1_INTEGER 0x02
#define ASN1_BIT_STRING 0x03
#define ASN1_OCTET_STRING 0x04
#define ASN1_NULL 0x05
#define ASN1_OID 0x06
#define ASN1_UTF8_STRING 0x0C
#define ASN1_SEQUENCE 0x10
#define ASN1_SET 0x11
#define ASN1_PRINTABLE_STRING 0x13
#define ASN1_T61_STRING 0x14
#define ASN1_IA5_STRING 0x16
#define ASN1_UTC_TIME 0x17
#define ASN1_GENERALIZED_TIME 0x18
#define ASN1_UNIVERSAL_STRING 0x1C
#define ASN1_BMP_STRING 0x1E
#define ASN1_PRIMITIVE 0x00
#define ASN1_CONSTRUCTED 0x20
#define ASN1_CONTEXT_SPECIFIC 0x80
/* \} name */
/* \} addtogroup x509_module */ /* \} addtogroup x509_module */
/* /*
@ -141,9 +95,6 @@
#define X509_ISSUER 0x01 #define X509_ISSUER 0x01
#define X509_SUBJECT 0x02 #define X509_SUBJECT 0x02
/** Returns the size of the binary string, without the trailing \\0 */
#define OID_SIZE(x) (sizeof(x) - 1)
#define OID_X520 "\x55\x04" #define OID_X520 "\x55\x04"
#define OID_CN OID_X520 "\x03" #define OID_CN OID_X520 "\x03"
@ -281,24 +232,12 @@
/** /**
* Type-length-value structure that allows for ASN1 using DER. * Type-length-value structure that allows for ASN1 using DER.
*/ */
typedef struct _x509_buf typedef asn1_buf x509_buf;
{
int tag; /**< ASN1 type, e.g. ASN1_UTF8_STRING. */
size_t len; /**< ASN1 length, e.g. in octets. */
unsigned char *p; /**< ASN1 data, e.g. in ASCII. */
}
x509_buf;
/** /**
* Container for ASN1 bit strings. * Container for ASN1 bit strings.
*/ */
typedef struct _x509_bitstring typedef asn1_bitstring x509_bitstring;
{
size_t len; /**< ASN1 length, e.g. in octets. */
unsigned char unused_bits; /**< Number of unused bits at the end of the string */
unsigned char *p; /**< Raw ASN1 data for the bit string */
}
x509_bitstring;
/** /**
* Container for ASN1 named information objects. * Container for ASN1 named information objects.
@ -315,12 +254,7 @@ x509_name;
/** /**
* Container for a sequence of ASN.1 items * Container for a sequence of ASN.1 items
*/ */
typedef struct _x509_sequence typedef asn1_sequence x509_sequence;
{
x509_buf buf; /**< Buffer containing the given ASN.1 item. */
struct _x509_sequence *next; /**< The next entry in the sequence. */
}
x509_sequence;
/** Container for date and time (precision in seconds). */ /** Container for date and time (precision in seconds). */
typedef struct _x509_time typedef struct _x509_time

1
library/CMakeLists.txt
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@ -3,6 +3,7 @@ OPTION(USE_SHARED_POLARSSL_LIBRARY "Build PolarSSL as a shared library." OFF)
set(src set(src
aes.c aes.c
arc4.c arc4.c
asn1parse.c
base64.c base64.c
bignum.c bignum.c
camellia.c camellia.c

3
library/Makefile
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@ -22,7 +22,8 @@ DLEXT=so
# Windows shared library extension: # Windows shared library extension:
# DLEXT=dll # DLEXT=dll
OBJS= aes.o arc4.o base64.o \ OBJS= aes.o arc4.o asn1parse.o \
base64.o \
bignum.o camellia.o certs.o \ bignum.o camellia.o certs.o \
cipher.o cipher_wrap.o debug.o \ cipher.o cipher_wrap.o debug.o \
des.o dhm.o havege.o \ des.o dhm.o havege.o \

260
library/asn1parse.c Normal file
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@ -0,0 +1,260 @@
/*
* Generic ASN.1 parsing
*
* Copyright (C) 2006-2011, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "polarssl/config.h"
#if defined(POLARSSL_ASN1_PARSE_C)
#include "polarssl/asn1.h"
#if defined(POLARSSL_BIGNUM_C)
#include "polarssl/bignum.h"
#endif
#include <string.h>
#include <stdlib.h>
#include <time.h>
/*
* ASN.1 DER decoding routines
*/
int asn1_get_len( unsigned char **p,
const unsigned char *end,
size_t *len )
{
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
if( ( **p & 0x80 ) == 0 )
*len = *(*p)++;
else
{
switch( **p & 0x7F )
{
case 1:
if( ( end - *p ) < 2 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = (*p)[1];
(*p) += 2;
break;
case 2:
if( ( end - *p ) < 3 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = ( (*p)[1] << 8 ) | (*p)[2];
(*p) += 3;
break;
case 3:
if( ( end - *p ) < 4 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = ( (*p)[1] << 16 ) | ( (*p)[2] << 8 ) | (*p)[3];
(*p) += 4;
break;
case 4:
if( ( end - *p ) < 5 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = ( (*p)[1] << 24 ) | ( (*p)[2] << 16 ) | ( (*p)[3] << 8 ) | (*p)[4];
(*p) += 5;
break;
default:
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
}
}
if( *len > (size_t) ( end - *p ) )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
return( 0 );
}
int asn1_get_tag( unsigned char **p,
const unsigned char *end,
size_t *len, int tag )
{
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
if( **p != tag )
return( POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
(*p)++;
return( asn1_get_len( p, end, len ) );
}
int asn1_get_bool( unsigned char **p,
const unsigned char *end,
int *val )
{
int ret;
size_t len;
if( ( ret = asn1_get_tag( p, end, &len, ASN1_BOOLEAN ) ) != 0 )
return( ret );
if( len != 1 )
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
*val = ( **p != 0 ) ? 1 : 0;
(*p)++;
return( 0 );
}
int asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val )
{
int ret;
size_t len;
if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
return( ret );
if( len > sizeof( int ) || ( **p & 0x80 ) != 0 )
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
*val = 0;
while( len-- > 0 )
{
*val = ( *val << 8 ) | **p;
(*p)++;
}
return( 0 );
}
#if defined(POLARSSL_BIGNUM_C)
int asn1_get_mpi( unsigned char **p,
const unsigned char *end,
mpi *X )
{
int ret;
size_t len;
if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
return( ret );
ret = mpi_read_binary( X, *p, len );
*p += len;
return( ret );
}
#endif /* POLARSSL_BIGNUM_C */
int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
asn1_bitstring *bs)
{
int ret;
/* Certificate type is a single byte bitstring */
if( ( ret = asn1_get_tag( p, end, &bs->len, ASN1_BIT_STRING ) ) != 0 )
return( ret );
/* Check length, subtract one for actual bit string length */
if ( bs->len < 1 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
bs->len -= 1;
/* Get number of unused bits, ensure unused bits <= 7 */
bs->unused_bits = **p;
if( bs->unused_bits > 7 )
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
(*p)++;
/* Get actual bitstring */
bs->p = *p;
*p += bs->len;
if( *p != end )
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
return 0;
}
/*
* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
*/
int asn1_get_sequence_of( unsigned char **p,
const unsigned char *end,
asn1_sequence *cur,
int tag)
{
int ret;
size_t len;
asn1_buf *buf;
/* Get main sequence tag */
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( ret );
if( *p + len != end )
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
while( *p < end )
{
buf = &(cur->buf);
buf->tag = **p;
if( ( ret = asn1_get_tag( p, end, &buf->len, tag ) ) != 0 )
return( ret );
buf->p = *p;
*p += buf->len;
/* Allocate and assign next pointer */
if (*p < end)
{
cur->next = (asn1_sequence *) malloc(
sizeof( asn1_sequence ) );
if( cur->next == NULL )
return( 1 );
cur = cur->next;
}
}
/* Set final sequence entry's next pointer to NULL */
cur->next = NULL;
if( *p != end )
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
return( 0 );
}
#endif

221
library/x509parse.c
View File

@ -1,7 +1,7 @@
/* /*
* X.509 certificate and private key decoding * X.509 certificate and private key decoding
* *
* Copyright (C) 2006-2010, Brainspark B.V. * Copyright (C) 2006-2011, Brainspark B.V.
* *
* This file is part of PolarSSL (http://www.polarssl.org) * This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@ -39,6 +39,7 @@
#if defined(POLARSSL_X509_PARSE_C) #if defined(POLARSSL_X509_PARSE_C)
#include "polarssl/x509.h" #include "polarssl/x509.h"
#include "polarssl/asn1.h"
#include "polarssl/pem.h" #include "polarssl/pem.h"
#include "polarssl/des.h" #include "polarssl/des.h"
#include "polarssl/md2.h" #include "polarssl/md2.h"
@ -57,224 +58,6 @@
#include <stdio.h> #include <stdio.h>
#endif #endif
/*
* ASN.1 DER decoding routines
*/
static int asn1_get_len( unsigned char **p,
const unsigned char *end,
size_t *len )
{
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
if( ( **p & 0x80 ) == 0 )
*len = *(*p)++;
else
{
switch( **p & 0x7F )
{
case 1:
if( ( end - *p ) < 2 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = (*p)[1];
(*p) += 2;
break;
case 2:
if( ( end - *p ) < 3 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = ( (*p)[1] << 8 ) | (*p)[2];
(*p) += 3;
break;
case 3:
if( ( end - *p ) < 4 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = ( (*p)[1] << 16 ) | ( (*p)[2] << 8 ) | (*p)[3];
(*p) += 4;
break;
case 4:
if( ( end - *p ) < 5 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
*len = ( (*p)[1] << 24 ) | ( (*p)[2] << 16 ) | ( (*p)[3] << 8 ) | (*p)[4];
(*p) += 5;
break;
default:
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
}
}
if( *len > (size_t) ( end - *p ) )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
return( 0 );
}
static int asn1_get_tag( unsigned char **p,
const unsigned char *end,
size_t *len, int tag )
{
if( ( end - *p ) < 1 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
if( **p != tag )
return( POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
(*p)++;
return( asn1_get_len( p, end, len ) );
}
static int asn1_get_bool( unsigned char **p,
const unsigned char *end,
int *val )
{
int ret;
size_t len;
if( ( ret = asn1_get_tag( p, end, &len, ASN1_BOOLEAN ) ) != 0 )
return( ret );
if( len != 1 )
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
*val = ( **p != 0 ) ? 1 : 0;
(*p)++;
return( 0 );
}
static int asn1_get_int( unsigned char **p,
const unsigned char *end,
int *val )
{
int ret;
size_t len;
if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
return( ret );
if( len > sizeof( int ) || ( **p & 0x80 ) != 0 )
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
*val = 0;
while( len-- > 0 )
{
*val = ( *val << 8 ) | **p;
(*p)++;
}
return( 0 );
}
static int asn1_get_mpi( unsigned char **p,
const unsigned char *end,
mpi *X )
{
int ret;
size_t len;
if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
return( ret );
ret = mpi_read_binary( X, *p, len );
*p += len;
return( ret );
}
static int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
x509_bitstring *bs)
{
int ret;
/* Certificate type is a single byte bitstring */
if( ( ret = asn1_get_tag( p, end, &bs->len, ASN1_BIT_STRING ) ) != 0 )
return( ret );
/* Check length, subtract one for actual bit string length */
if ( bs->len < 1 )
return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
bs->len -= 1;
/* Get number of unused bits, ensure unused bits <= 7 */
bs->unused_bits = **p;
if( bs->unused_bits > 7 )
return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
(*p)++;
/* Get actual bitstring */
bs->p = *p;
*p += bs->len;
if( *p != end )
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
return 0;
}
/*
* Parses and splits an ASN.1 "SEQUENCE OF <tag>"
*/
static int asn1_get_sequence_of( unsigned char **p,
const unsigned char *end,
x509_sequence *cur,
int tag)
{
int ret;
size_t len;
x509_buf *buf;
/* Get main sequence tag */
if( ( ret = asn1_get_tag( p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
return( ret );
if( *p + len != end )
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
while( *p < end )
{
buf = &(cur->buf);
buf->tag = **p;
if( ( ret = asn1_get_tag( p, end, &buf->len, tag ) ) != 0 )
return( ret );
buf->p = *p;
*p += buf->len;
/* Allocate and assign next pointer */
if (*p < end)
{
cur->next = (x509_sequence *) malloc(
sizeof( x509_sequence ) );
if( cur->next == NULL )
return( 1 );
cur = cur->next;
}
}
/* Set final sequence entry's next pointer to NULL */
cur->next = NULL;
if( *p != end )
return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
return( 0 );
}
/* /*
* Version ::= INTEGER { v1(0), v2(1), v3(2) } * Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/ */